Olaf Stapledon was an odd duck. Born long enough ago to remember when Queen Elizabeth was alive and kicking. Wrote about humanity's descendents living on a terraformed Neptune, where they've hacked themselves to have 96 genders and resemble anthropomorphic animals.

(And also have a third upwards-facing eye and telepathically communicate with themselves a half a Neptune year in the past so they can star-watch in 3D.)